(a) Field of the Invention
The present disclosure relates to a pump module.
(b) Description of the Related Art
In general, in order to reduce nitrogen oxide (NOx) that is contained in an exhaust gas, an exhaust system of a diesel engine has an exhaust gas post-processing apparatus such as Selective Catalyst Reduction (SCR), Diesel Oxidation Catalyst (DOC), and Catalyzed Particulate Filter (CPE).
An exhaust gas post-processing apparatus (hereinafter, referred to as an ‘SCR apparatus’) to which SCR is applied performs a function of reducing nitrogen oxide of an exhaust gas to nitrogen and oxygen by ejecting a reducing agent such as an urea aqueous solution to the inside of an exhaust pipe.
That is, in the SCR apparatus, when a reducing agent is ejected to the inside of the exhaust pipe, the reducing agent is converted to ammonia (NH3) by a heat of an exhaust gas, and as a catalyst reaction of nitrogen oxide and ammonia in an exhaust gas by an SCR catalyst, the nitrogen oxide may be reduced to a nitrogen gas (N2) and water (H2O).
In this way, in order to eject a urea aqueous solution to the inside of the exhaust pipe through the SCR apparatus, a urea aqueous solution supply system for supplying the urea aqueous solution to the SCR apparatus is required.
The urea aqueous solution supply system generally has a urea tank that stores a urea aqueous solution and a pump module that is formed in the urea tank and that supplies the urea aqueous solution to the SCR apparatus.
In the conventional art, it is difficult to assemble a pressure sensor in a flange and to dispose a plurality of components at a limited space. Further, a sensor, a pump terminal, and a heater that are mounted in the flange may be corroded by a urea aqueous solution of strong basicity.
In the conventional art, there is difficulty in stably pumping a strongly basic urea aqueous solution to an injector. Further, as a heating apparatus and a pump are installed at a predetermined distance, it is not easy to melt a frozen urea aqueous solution existing within the pump.
Further, in the conventional art, when a vehicle having a filter is inclined, particulates are not evenly filtered through the filter.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.